This section provides background information related to the present disclosure which is not necessarily prior art.
Turbocharged engines utilize compressed air which results in a larger quantity of air being forced into the engine, creating more power. The energy used to drive the turbo compressor is extracted from waste exhaust gases. As the exhaust gases leave the engine, they are directed through a turbine wheel placed in the exhaust flow. The gases drive the turbine wheel, which is directly connected via a turbine shaft to a compressor wheel. Increased exhaust gas flow drives the turbine wheel faster, providing the engine more air, thereby producing more power. Therefore, the turbocharger uses the extraction of energy from the exhaust gas to improve the engine efficiency.
Turbochargers are usually seen as power enhancement on performance cars, but today, turbochargers are becoming more regularly used to provide greater torque on small capacity engines. The advantages of using a turbocharged engine include improved fuel efficiency and reduced exhaust emissions. The components of the turbocharger generally include a housing defining a compressor chamber and a turbine chamber, a compressor wheel is disposed in the compressor chamber, and a turbine wheel is disposed in the turbine chamber. A turbine shaft is provided for connecting between the turbine wheel and the compressor wheel.
A conventional turbocharger can include a center housing between the turbine housing and a back plate of the compressor. The center housing can support a bearing cartridge for rotatably supporting the turbine shaft. This arrangement requires tight tolerances on all of the housing components in order to precisely control the position of the turbine and compressor wheels relative to the housing components. As the housing components are assembled to one another, the blade tip clearance of the compressor and turbine wheels need to be precisely controlled to provide an efficient turbocharger.